1. Field of the Invention
The present invention relates to a linear vibrator, and more particularly, to a linear vibrator capable of generating vibrations when mounted in a portable electronic device.
2. Description of the Related Art
Recently, the release of personal portable terminals having large LCD screens provided for user convenience has significanity increased. Accordingly, a touch screen scheme has been adopted therein, and a vibration motor has been used so as to generate vibrations when a touch is applied to a touch screen.
The vibration motor converts electrical energy into mechanical vibrations using a principle of generating electromagnetic force, and is mounted in the personal portable terminal to be used for silent incoming signal notification.
In the related art, a method in which a rotation part of an unbalanced mass is rotated by generating rotational force to thereby obtain mechanical vibrations has been used, and the rotational force is subjected to a rectifying action via a contact point between a brush and a commutator to thereby obtain the mechanical vibrations.
However, a brush-type structure using the commutator may cause mechanical friction and electrical sparks as well as the generation of foreign objects when the brush passes through a clearance between segments of the commutator when the motor is rotated, so that the service life of the motor may be shortened.
In addition, since it takes time to reach an amount of target vibrations due to rotational inertia when voltage is applied to the motor, there may be a problem in which a sufficient amount of vibrations for the touch screen may not be implemented.
A linear vibrator is widely used to implement a vibration function in the touch screen, while overcoming disadvantages in the service life and response properties of the motor.
The linear vibrator does not use a motor rotation principle, but generates resonance by periodically generating, in accordance with resonant frequencies, electromagnetic force obtained through a spring installed inside the linear vibrator and a mass body suspended thereon, thereby generating vibrations.
The linear vibrator can be slimmer and more effectively produced to meet market trends for compact and slim-type portable electronic devices, and there should be no influence on the performance and characteristics of the vibrator even in the case that several factors act thereupon.
However, a linear vibrator according to the related art have a problem in that the performance and characteristics thereof are changed by components that vibrate in an interior space of the linear vibrator, and this may eventually affect the portable electronic device adopting the above-described linear vibrator.
Accordingly, there is an urgent need for research that may help to prevent the performance and characteristics of the vibrator from being changed by components that vibrate in the interior space of the linear vibrator.